.\" This file is free software, distributed under the BSD license.
.Dd May 31, 1993
.Dt drop4 6
.Os
.Sh NAME
.Nm drop4
.Nd the game of drop4
.Sh SYNOPSIS
.Nm
.Op level
.Sh DESCRIPTION
.Nm
is a tetromino packing game. The object is to fit the shapes together
forming complete rows, which then vanish. When the shapes fill up to
the top, the game ends. You can optionally select a level of play.
.Pp
The default level of play is 1.
.Pp
The default control keys are as follows:
.Pp
.Bl -tag -width "xxspacexx" -compact -offset indent
.It j
move left
.It k
rotate 1/4 turn counterclockwise
.It l
move right
.It Aq space
drop
.It p
pause
.It q
quit
.El
.Pp
Play level can be given as an argument to the program.
.El
.Pp
.Sh PLAY
At the start of the game, a shape will appear at the top of the screen,
falling one square at a time. The speed at which it falls is determined
directly by the level: if you select level 2, the blocks will fall
twice per second; at level 9, they fall 9 times per second. (As the
game goes on, things speed up, no matter what your initial selection.)
When this shape
.Dq touches down
on the bottom of the field, another will appear at the top.
.Pp
You can move shapes to the left or right, rotate them counterclockwise,
or drop them to the bottom by pressing the appropriate keys. As you fit
them together, completed horizontal rows vanish, and any blocks above
fall down to fill in. When the blocks stack up to the top of the screen,
the game is over.
.Sh SCORING
The score list is produced at the end of the game. The printout includes
each player's overall ranking, name, score, and how many points were
scored on what level.
.Dq * .
.Sh FILES
.Bl -tag -width /var/lib/bsdgames/drop4.scoresxx
.It /var/lib/bsdgames/drop4.scores
high score file
.El
.Sh AUTHORS
Adapted from a 1989 International Obfuscated C Code Contest winner by
Chris Torek and Darren F. Provine.
.Pp
Manual adapted from the original entry written by Nancy L. Tinkham and
Darren F. Provine.
.Pp
Code for previewing next shape added by Hubert Feyrer in 1999.
